Abstract: The subject matter relates to an applicator for applying matter to be applied, such as vaccine, to animals. The applicator includes an applicator head which incorporates a chamber and needle. The needle is at least partially surrounded by a generally elongate proboscis or cover which is capable of axial movement over and relative to the needle. A reservoir for matter to be applied or vaccine, is provided and is attached to the applicator head. Valving connects the chamber with the needle and also connects the reservoir with the chamber. Predetermined axial movement of the proboscis or cover relative to the needle opens the valving between the needle and chamber and allows matter within the chamber, such as vaccine, to be passed from the chamber through the needle. The chamber is provided with a movable wall and actuating means connected to a trigger.